WASHINGTON, Nov. 4 — In the wake of accusations by a former male escort that the Rev. Ted Haggard had a three-year sexual relationship with him, an independent oversight board at Mr. Haggard’s New Life Church found that he had “committed sexually immoral conduct” on Saturday and dismissed him as senior pastor.

Over the last few days, Mr. Haggard’s career as the founder of the 14,000-member New Life megachurch in Colorado Springs and as leader of the National Association of Evangelicals has crumbled under the weight of the accusations and his explanations. He initially denied knowing the former escort, Michael Jones, 49, of Denver. By Friday, Mr. Haggard revised his account and said he had gotten a massage from Mr. Jones and bought methamphetamine from him. Mr. Jones has denied selling drugs. Mr. Haggard said he never used the drugs. He has publicly denied any sexual relationship.

Nonetheless, he resigned on Thursday as president of the evangelical association and stepped down temporarily as the senior pastor of New Life until its Overseer Board, an independent panel made up of four pastors from other churches, completed an investigation.

In a one-page statement issued Saturday afternoon, the board said, “Our investigation and Pastor Haggard’s public statements have proven without a doubt that he has committed sexually immoral conduct.”

The statement, which was made available by the church’s lawyer, L. Martin Nussbaum, did not elaborate on the nature of the immoral conduct, and it did not cite specific statements Mr. Haggard made. The statement also suggested that the board did not speak to Mr. Jones, but Mr. Nussbaum could not be reached for further clarification.

“In consultation with leading evangelicals and experts familiar with the type of behavior Pastor Haggard has demonstrated, we have decided that the most positive and productive direction for our church is his dismissal,” the statement said. “Pastor Haggard and his wife have been informed of this decision. They have agreed as well that he should be dismissed.”